When to take L-Lysine | PlanYourVitamins.com

What is L-lysine good for?

Short answer: L-lysine has potential benefits for stress, anxiety, the immune system, bone health, calcium absorption, collagen production and mental health.

L-lysine is an essential amino acid that serves as an important building block for proteins. Our body cannot produce L-lysine by itself, so we need to obtain it from our diet, mostly through animal products, although L-lysine supplementation is also an option.

Role in the immune system

In addition to its protein-building qualities, L-lysine is also known to enhance the function of the immune system, and a good bellwether of a strong immune system is how well it deals with the Herpes simplex virus.

This virus often manifests itself in the form of cold sores and blisters that appear around the mouth area when our immune system is weakened and cannot keep the virus in check. Studies suggest that L-lysine supplementation could prevent the virus from replicating, and also reduce the overall duration of the cold sores.

Benefits for stress & anxiety

The occurrence of cold sores is often associated with an increase in stress, and L-lysine is thought to play an important role in how we manage stress and anxiety. An animal study performed in 2003 revealed that L-lysine can block receptors that are involved in our stress response. The researchers in the study observed that when rats were given L-lysine, they had reduced rates of stress-induced loose bowel movements.

A further study the following year by the same researchers found that adding L-lysine supplementation to wheat flour in Syrian villages reduced overall anxiety scores in male participants that had elevated stress levels, while female participants noticed a reduction in cortisol levels.

Role in bone health

L-lysine's role in bone health is two-fold. Firstly, L-lysine is involved in the way in which our body absorbs calcium, and therefore has a positive effect on bone mineralization in aging adults. In addition to that, it also promotes wound healing, by encouraging the formation of collagen, which is a major component of bone structure.

When should I take L-lysine?

Short answer: L-lysine is best taken on an empty stomach, at least 2 hours since the last meal and at least 30 minutes before the next meal.

Although there is no particular time of day that has been found to be best suited for taking L-lysine, it is best absorbed when taken on an empty stomach, between meals. Specifically, studies show that dietary protein reduces the effectiveness of supplemental L-lysine, so if for whatever reason you must take your L-lysine with food, try aiming for a low-protein meal to get the most out of the L-lysine.

What does L-lysine combine well with?

Short answer: L-Lysine has been shown to work well together with L-arginine, L-proline and vitamin C.

L-lysine with L-arginine, for bone health and mood

As mentioned above, L-lysine is known to promote bone health. Studies suggest that when L-lysine is combined with L-arginine, it promotes bone-building activity and enhances the production of collagen even further.

This is thought to be due to the way in which both amino acids use the same pathways in the body. This same combination has also been documented to regulate hormonal stress responses in humans that suffer from high trait anxiety.

That said, elevated levels of L-arginine could actually lower the level of L-lysine in your body, so it is advised to take both in their recommended doses in order to avoid them from competing with each other for the same pathways.

L-lysine with vitamin C and L-proline, for cardiovascular health

You may have heard of a heart-healing protocol devised by the great Linus Pauling that involved taking elevated amounts of L-lysine and L-proline, together with large quantities of vitamin C, for the purpose of clearing arteries of plaque caused by atherosclerosis.

There are several mechanisms through which this works, but in summarized form, the L-lysine binds to the lipoproteins from which these plaques are formed, and helps to dissolve them, while the combination of all three supplements encourages the formation of new collagen, the structural framework from which healthy arteries are formed, or in this case, repaired and regenerated.

What should I avoid taking L-lysine with?

Short answer: Avoid taking L-lysine supplements at the same time as calcium.

Avoid with calcium

Due to the way in which L-lysine increases how much calcium your body absorbs, it is advisable to avoid taking high doses of calcium, in particular calcium supplements, at the same time as taking L-lysine supplements.

Who should avoid taking L-lysine supplements?

Short answer: People under the following conditions should check with a trusted doctor before taking L-lysine supplements: Kidney problems, liver problems.

People with liver or kidney problems

L-lysine supplementation is not recommended for people that suffer from health conditions that affect the liver or kidneys, so be sure to check with your trusted doctor first before taking L-lysine supplements if you are concerned that you might fall into this category.

What are natural sources of L-lysine?

If you are interested in achieving your daily L-lysine intake through your diet, rich sources of L-lysine include:

Beef
Chicken
Eggs
Sardines
Cod
Parmesan cheese
Legumes
Soybeans
Seeds
Nuts
Avocados

L-Lysine data sources & further reading

Last updated by Asklepios on 30th January, 2025